Steel stud anchor

ABSTRACT

A metal anchoring fastener fastens millwork onto walls constructed with wall cladding fastened to steel studs. The load typical of a loaded cabinet is borne by the steel stud anchors owing to the mate between the profile of the steel stud anchor and the layers of millwork and wall cladding and steel stud that said anchor penetrates. The pitch of the thread adorning the profile of the steel stud anchor progresses non-linearly along the length of said shaft, the shaft is generally non-linear in profile, and the thread profile is non-uniform along the length of said shaft. The anchor can also support a secondary screw concentrically penetrating the void at the center of the anchor, in order to hang loads from a wall, with or without millwork. Predrilling of the holes can enable installation of these zinc anchors.

FIELD OF THE INVENTION

This Invention relates generally to fasteners and more particularly tofasteners detailed to anchor in steel studs supporting walls inbuildings.

BACKGROUND OF THE INVENTION

For generations, homes were framed with timber, with the interiors cladin drywall or some sort of wallboard. In a traditional wood-framed home,hanging things from the walls was neither difficult nor precarious.Mainly 2″×4″s and 2″×6″s were used. After the framing was finished,drywall or some wall board surface would be attached to the framingmembers, it would be painted and then the millwork would be attached,such as a kitchen cabinet, a bathroom vanity, book cases etc. Thesesolid wooden studs were sturdy and the process, although wasteful,allowed builders and homeowners alike to easily fasten millwork andother heavy objects to walls by using a wood screw to connect themillwork to the structural timber framing members of the home. The solidwood stud provided plenty of surface contact to a fastener or wood screwand plenty of tensile strength to hold the fastener or wood screw inplace and support the weight of e.g. cabinets and shelves being fastenedto the walls. The use of a solid wood stud and a properly sized woodscrew remains the preferred and usual method to install carpentry andmillwork.

Wood screws typically have a straight shaft or body with a consistentdiameter having a pointed tip at on one end and with a regular spacedthread winding its way up the shaft to the head of the screw located atthe end opposite the pointed tip. Wood is somewhat elastic and tends tohold its form. The straight shaft and regular thread of the wood screwin turn allows the screw to squeeze between the wood fibers of a solidwood stud, giving plenty of surface contact between the wooden framingmember and the screw and allowing the wood stud to hold it along itswhole surface. This is why wood screws in wood framed homes work well.

Many other kinds of threaded fasteners exist with these fasteners beingdistinguished by their varied tightening features, shaft profiles,thread pitch, thread profile, terminal piercing and cutting features andthe materials the fasteners are made of. For example, sheet metal screwsdesigned for use with sheet metal are also known. These screws aresimilar to wood screws in that they typically have a straight shaft,consistent diameter leading to a pointed tip and a regularly spacedthread.

When a lighter object is to be hung, a drywall anchor can used instead.With its small pilot hole, a drywall anchor can be twisted straight intowall board regardless of the location of stud. In fact, it is preferablewhen using wall anchors to avoid the wood studs entirely as they aredesigned to be applied strictly to drywall. However, drywall anchors aregenerally load rated at only around 50 lbs.

In recent years, builders have begun using steel framed partitions instructures like condominiums and commercial towers. Steel studconstruction is popular with builders of condos, offices and even somehomes because it saves lots of time and materials for builders andhomeowners alike, resulting in cost savings and more efficient use oflabor. Most high-rise structures in cities today are framed this way.

Steel stud construction is not without its problems, however. Forexample, the light gauge and weight of the steel studs has made itextremely difficult and time consuming to fasten most things to walls.(e.g. cabinets, shelves, artwork, large screen televisions, pictures). Atypical interior partition framed with steel studs has a drywall facejust like the wooden framed wall but the studs inside are hollow andquite flimsy. Viewed in section from above, a steel stud looks like theletter “C”, as steel studs are closed on 3 sides and hollow. Steel studsonly become structurally strong when fastened to the cement slab aboveand below (or the floor and ceiling) as well as attached to the otherframing members, drywall or wallboard. In other words, steel framedstructures become strong when assembled in unison with the otherbuilding components.

Conventional wood or sheet metal screws were not designed for use with athin, hollow steel stud because the steel stud offers little surfacecontact/contact substance for the screw threads to hold on to. Whencoupled with the fact that the steel studs are quite malleable andeasily distorted, the result is a poor match of fastener and framingmember. The wood and sheet metal screws stretch the hole they make in asteel stud and then can't be properly snugged up. Further, the wood andsheet metal screws strip easily and they do not secure well to the sheetmetal that is within a wall. As a conventional metal or wood screw istightened in a steel stud, it winds in adequately, but when an attemptis made to turn the thread a final time to secure the screw in the steelstud, the metal of the steel stud is displaced and the slender straightscrew easily slips loose.

Drywall anchors designed for use in drywall, are no better in steelstuds. Drywall anchors are designed to cut into the gypsum wall boardand hold tight like a plug. These screws are often too short to reachthe steel stud behind the drywall. When they can be threaded into a holein a steel stud, they have similar issues as wood and sheet metalscrews, such as tearing of the hole and stripping of the screw. Further,drywall anchors are only rated for light weight applications.

To address the problem of fastening millwork to steel studs, buildershave come up with a number of work-arounds, but these work-arounds haveproven time consuming and costly, with none addressing the problemdirectly or effectively. A commercial builder often winds up applying alayer of plywood behind the drywall on the face of the steel studs togive the millwork installers something to screw the cabinets to. Inother cases, the studs are cut and altered and a strip of plywood isplaced along the face of the studs behind the drywall. Thesealternatives are slow, time consuming, indirect and also quite pricey,not to mention inferior to simply screwing into wooden studs. Acontractor installing anything heavy in a steel framed home or officelikely will need to open the wall and pack some wood of their own insidethe framing behind the drywall to give something to screw into that willhold fast. This means that before e.g. the millwork can be installed,the wall must first be cut open, the wood put inside and then thedrywall must be painted and plaster repaired. Builders have also usedcombinations of construction adhesives and toggle bolts or butterflyclips applied through the drywall to hang e.g. millwork, but these stillare only rated for only about 250-275 lbs depending on the gauge of thehardware.

Thus, there is a need for a fastener that can fasten securely in a steelstud and can secure heavy objects, such as large TV's, cabinets andbookshelves.

As discussed in the present application, “millwork” refers to a woodenwall furnishings, including bookshelves and cabinets. “Wall cladding”refers to a plurality of generally planar materials fastened verticallyto vertical support studs, exemplified by gypsum wallboard. “Steelstuds” are vertical struts formed by the folding of sheet metal toresist bending. When fastened from floor to upper beam, said steel studsform walls to which wall cladding, generally gypsum wallboard, andmillwork, such as cabinets, are applied. An “anchor” refers to afastener that forms a mate with a substrate, such as drywall to bear aload. The “mate” refers to the piercing and threading into a substrateof a threaded fastener, also called a “screw”, exemplified by a screwmated to a wall by driving it in with a screwdriver, whether manual orpower-driven. “Linear” describes the relationship of a dependentvariable increasing in a straight line function with an increase in theindependent variable. “Non-linear” refers to the relationship functiondescribed by a curve.

The “tightening features” refers to the openings in the head of afastener into which a drive bit is fitted to enable rotation of thescrew head, with the screw head being a flanged accouterment crowning athreaded shaft. The “shaft profile” describes the change of diameter ofthe shaft down the length of the shaft. Known shaft profiles include ashaft with a meeting of two straight lines, a “linear” shaft, or twocurves (i.e. “non-linear” shaft). Generally conical shafts equipped withhelical threads will translate a rotational force applied to the headinto a perpendicular linear displacement into the material to which thefastener is applied. The “thread pitch” describes the number ofrotations of the thread per linear unit of shaft length. An “aggressive”thread has a widely spaced helical ridge. Thread can be “linear”, thatis, unchanging along the length of the shaft, or “non-linear”, whereinthe thread count varies along the long axis of the fastener shaft.“Thread profile”, the cross-sectional shape and dimensions of the threadridge as it winds around the shaft, can be uniform or non-uniform alongthe thread helix. Changing thread pitch and thread profile along theshaft can result in different qualities of mate between the fastener andthe material being fastened into. The choice of “materials” can affectthe hardness, brittleness, and tensile strength of the fastener, all ofwhich will determine the quality of the mate with the substrate intowhich the fastener is fastened. Finally, at the terminal point of theshaft a plurality of “cutting” features and “piercing” features can beincorporated to add the entry of the fastener into the substrate. Saidcutting and piercing features are affected by materials and geometry.

Lopez (U.S. Pat. No. 4,473,984: Oct. 2, 1984) presents a threaded studthat is meant to penetrate any masonry, wood, or steel stud wall topresent a loop transverse to the stud thread helix emanating from thewall said threaded stud has penetrated. While no claims or descriptionare made of the threaded stud, the patent specification does identifythat the manner of thread and cutters can influence the thread mate.Diagrams for this patent indicate a threaded stud or shaft that isidentical in cross-section from base to just before the conical pointedtip. Non-linear shaft profiles, linear thread pitch progressions,non-uniform progression of thread profile are all not discussed in termsof their influence on mate between the anchor and the wall. The threadedstud of the Lopez patent would not be suitable for fastening with asteel stud for the same reasons as a wood screw or sheet metal screw.The thin steel stud would distort easily with the described threadedstud with the point of entry (pilot hole) being easily displaced, suchthat this fastener would lose its grip and not secure properly

Bui (U.S. Pat. No. 8,601,763: Dec. 10, 2013) describes a noveltyspecific to the metal studs discussed in this Application. The rivets orscrews of the Bui patent purportedly connect a thin concrete slab to ametal frame. Thus, the Bui patent describes a rivet to be appliedbetween ribs of a steel stud into screws supported a concrete panel canbe drilled. This static implementation of a mate in the steel studitself presupposes the ability to find this mate rivet when hanging thewall cladding to the steel studs. Such a fastener is very specificallydesigned for mating concrete to metal and would not be appropriate fore.g. drywall as it would break apart the drywall and therefore would nottighten properly in a steel stud application. [0016] Katsumi (U.S. Pat.Application 20060228186: Oct. 12, 2006) presents a self-tappingstainless steel screw with a built-in fracture line to remove the drillhead when drilling steel sheets for rooves and walls. What the steelsheets are being affixed to is not specified. No special attention isgiven to the thread, the thread profile, and the shaft profile, and thematerial used is not zinc. Such a fastener would not be suitable forfastening with a steel stud for the same reasons as a wood screw orsheet metal screw. The screw of the Katsumi patent is designed for usewith heavier gauge studs, for example the kind used in roofing truss,which is much heavier/thicker than the steel studs used behind anapartment's walls. The straight shaft and even threads of this screwwould strip easily in a steel stud. Further, these screws would workwell in shear forces but would not tension, because the cross section ofthe amount of material the threads grab is minimal.

SUMMARY OF THE INVENTION

This Application describes how the structure of the novel steel studanchor fastener constituting the Invention enters and, as it enters,alters the millwork, wall cladding, and steel stud to form aload-bearing mate. Accordingly, it is an objection of this invention toat least partially overcome some of the disadvantages of the prior art.

The problems with obtaining a fastener that will securely holdsignificant amounts of weight in a steel stud have been solved by thesteel stud anchor of the present invention. The present arrangementutilizes a helically threaded generally conical fastener equipped withtightening features in the head and piercing features in the point thatenable the fastener to be drilled through a wall and anchor to the steelstud supporting said wall. Pre-drilling a hole in preparation todrilling the anchor into the wall is also an installation option forthis anchor.

In preferred embodiments, the steel stud anchor has a unique concaveprofile of the shaft coupled with an unusual auger-like thread style andprogression which causes the steel stud to curl around the anchor andhold it fast. This allows for a far superior grip.

In certain embodiments of the present invention, the threads on theshaft are provided with an increased profile which makes them resistantto stripping when threaded into a steel stud hole. In furtherembodiments, the threads near the bottom of the shaft of the anchor(near the pointed tip) are closer together and become farther aparttoward the top of the anchor shaft (near the head). With thisconfiguration, as the anchor is screwed into the steel stud, the threadsare at first close together and then as it is wound in further, thethreads are thicker and further apart, such that the threads are used toshape the metal of the steel stud surrounding the anchor shaft much likethe way an ice cream scoop curls the ice cream while scooping. Theanchor can be applied directly through the millwork, the drywall anddirectly into the existing steel studs with no need for bulking up thewall with wood. Further, the studs of the present invention aretherefore capable of securing far greater weights in less time with lessskill and hassle.

With its different profile and thread style, the steel stud anchor ofthe present invention functions differently from prior art wood andmetal screws. As the steel stud anchor is threaded into a steel stud,the increasing diameter of the shaft of the anchor pulls the hole in thesteel stud open while the anchor threads also begin to tightly curl thedisplaced metal of the steel stud around the anchor, making the point ofentry stronger. This increased surface area around the anchor alsoallows for more surface contact between the anchor and the steel stud,giving it a much greater grab or purchase. Where previously knownfasteners are easily stripped when inserted into steel stud, it isextremely difficult to strip the steel stud of the present applicationwhen it is threaded into a steed stud. The greater grab or purchasewithout stripping, in turn, enables the anchor to deliver load ratingsmany times greater than anything else currently on the market. Incertain embodiments, the steel stud anchor of the present invention canhold approximately four times the load of the known prior art fasteners.The steel stud anchor of the present invention can, in certainembodiments, hold up to about 1000 lbs. In certain other embodiments,the steel stud fastener can hold greater than 1000 lbs securely. Theability to directly fasten the steel stud anchor to a steel stud saves amassive amount of labor and delivers a far superior attachment of heavycomponents to walls.

In certain embodiments, the steel stud anchor includes a self-drillingtip, allowing professionals to move more quickly and shoot the anchordirectly through the drywall, without drilling. In certain embodiments,a blade is located adjacent to the pointed end. In preferredembodiments, the blade is a small sharp flange that sits just adjacentand slightly recessed up the shaft from piercing tip of the anchor. Asthe anchor spins during its insertion, the sharp flange scores the steelstud's surface, assisting the tip in piercing the stud. In a preferredembodiment, the blade is approximately ⅛″ in length. In otherembodiments, a pilot hole can first be drilled before inserting thesteel stud anchor. In certain preferred embodiments, the pilot hole isapproximately 3/16″ in diameter. The steel stud anchor of the presentinvention can be made in a variety of sizes, for example, with a lengthof 3.5″, 3″, 2.5″, and 2″. In preferred embodiments, the length of theanchor is a general purpose size of 3.5″.

The anchor can also be provided with a secondary thread that adjacentthe head of the anchor and leads in to the primary thread discussedabove. In preferred embodiments, the secondary thread extends forapproximately ½″ below the head of the anchor. The secondary thread isslightly grooved to help it move more easily through e.g. drywall ormillwork. The spacing of the threads of the secondary thread are wideenough to allow for the thickness of a sheet of drywall. The purpose ofthe slightly grooved secondary thread is to keep e.g. the displaceddrywall or millwork (detritus) tightly packed as the anchor is screwedinto a wall to prevent the exposed surface of the wall or millwork fromblistering.

Once twisted tightly into the steel stud, the steel stud anchor can alsobe used as an anchor itself, such that in certain embodiments, a smallerscrew can be inserted, if desired. The steed stud anchor can also beused in conjunction with a variety of hooks, clips, hangers and anythingelse desired to be screwed in to a wall. The steel stud anchor can alsobe easily removed, unlike toggle bolts or butterfly clips.

In a preferred embodiment, the steel stud anchor of the presentinvention is about 3.5″ (about 8.9 cm) in length and can be about 17 mmor about ⅝″ across the head. The shaft below the head is about ⅜″ orabout 9.5 mm in diameter. In preferred embodiments, the taper (radius)and thread frequency (pitch) follow the relationship shown in FIG. 7which is based on a standard 3.5″ (about 8.9 cm) in length anchor. Forexample, in certain preferred embodiments, an anchor with a 3.5″ lengthhas an about 3/16″ diameter thread at the pointed tip end of the shaftand increases up to a diameter of about ⅝″ at the head end of the shaft.

However, the increase of the diameter is not a linear progression. Thechange in radius size from the tip to the head is generated using aFormula I discussed in the detailed description below. The anchordesigned using Formula I will have a concave curve to the shaft. Thepitch of the thread (crest to crest distance) starts off at about ⅛″ andincreases to about 5/16″ and is a linear transition (e.g. increase by afixed multiplier, e.g. ×*1.3) along the length of the threaded section.Formula I was developed to allow the small diameter of the anchor toenter the steel stud with less torque. As the anchor gets deeper intothe hole in the steel stud, the steel stud is being formed around thecore of the anchor that also follows the same curve as the change inradius formula (but using the minor diameter of the thread instead. Asthe pitch increases, so does the torque required to drive the anchorinto place. Eventually, when the anchor reaches the desired depth(usually with the head of anchor flush onto the drywall), the torque isat the maximum and so is its holding strength. The thread pitch formulaof Formula II (discussed in detail in the Detailed Description sectionbelow) is important to allow easy starting and maximum steel studforming (without tearing the steel stud). The thread radius of Formula Ialso aids in the ease of installation and steel stud formation but alsoacts as an auger when being installed. As the anchor passes through thedrywall and enters the steel stud, one revolution at the tip drives theanchor into the wall only about ⅛″. However the part of the anchor thathas not yet entered or passed through the steel stud has a larger pitch.This acts as an auger and pushes the debris from the hole in the drywallout of the way for the anchor. Eventually, the outside diameter of thearea near the tip of the anchor is equal to the core diameter of thehead end of the anchor creating a clean tight fit without over packingthe hole.

More particularly, the steel stud anchor of the present applicationprovides for anchoring perpendicularly into vertical steel studs in ableto support e.g. wall cladding, and, optionally, millwork and other heavyitems to be hung from a wall like televisions, artwork such as pictures,mirrors, utility hangers bike racks, audio equipment/home electronics,shoe racks, display cases, hand rails, planters, sconces, lightingfixtures, studio equipment, decorative wall panels applied on top ofdrywall (like in condo hallways) fire place mantel and surrounds,bathroom vanities and urinals. The fastener has a head equipped withtightening features arranged around an inner void that extends from thehead down into the shaft. The void functions as a screw drive, allowingfor torque to be applied to the screw to tighten it. Known screw driveshapes may be used such as a slot, a Phillips, Pozidriv, Square,Robertson, Hex, Hex socket (Allen), Security hex socket, Torx, SecurityTorx, Tri-Wing, Spanner head, Clutch, One-way, Double-square, Triplesquare, Polydrive, Spline drive, Double hex, Bristol, Pentalobular orother known shapes. In certain preferred embodiments, the screw drive isa Phillips head. In preferred embodiments, the void extends about 1″deep, starting from the opening in the head and extending down 1″ intothe body of the anchor.

In certain embodiments, the void is long enough and wide enough to allowfor insertion of caps or other anchors or fasteners. Said tighteningfeatures can be temporarily coupled to a complementary drive shaft inorder to drive said fastener into the wall. During this penetration ofthe fastener into the substrate, the helical thread winding around thegenerally conical fastener shaft translates the rotary motion applied tothe fastener head by the drill into a linear translation of the anchortoward the steel stud supporting the wall substrate of wall cladding andmillwork. A piercing point at the narrow point of the fastener distal tothe head causes the steel stud, when reached, to be pierced and allowsthe thread to fold over the metal to form a rigid anchor between thethread of the shaft with the newly rimmed perforation in the steel stud.Said penetration of said steel stud may be aided by predrilling of ahole prior to drilling in of the said anchor.

In a preferred embodiment, a wall is prepared by fixing steel studs attop and bottom to form a structure onto which wall cladding can befixed. Wall cladding is attached to the steel stud by means ofconventional fasteners. Using a power driver equipped with a bit thatmatches the tightening features of the fastener head, the fastener isdriven through the back wall of millwork such as a cabinet, through thewall cladding, and piercing the steel stud to form a mate that bearsload such as a loaded cabinet.

The anchor may be further pierced through the head by a secondaryordinary fastening screw to provide an anchor within an anchor.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which illustrate embodiments of the invention:

FIG. 1 shows a perspective front view of millwork fastened to a steelstud wall by steel stud anchors;

FIG. 2 shows a steel stud anchor in isometric view;

FIG. 3(a) is a top view of the steel stud anchor;

FIG. 3(b) is a cross-sectional view of the anchor of FIG. 3(a) alongline C-C′;

FIG. 4(a) is a top view of the anchor penetrated by a secondary screw;

FIG. 4(b) is a cross-sectional view of the anchor and screw of FIG. 4(a)along line D-D′;

FIG. 5(a) is a cross-sectional side view showing penetration of theanchor into the millwork and wall cladding;

FIG. 5(b) is a portion of the view of the rim formed in the steel studwall of FIG. 5(a) enlarged for magnification purposes.

FIG. 6 shows an isometric view of a finishing cap to be pressed into thevoid of the anchor head.

FIG. 7 shows a representation of the anchor of the present inventionindicating how the Radius and Pitch of the steel stud anchor at a pointZp along the thread (in FIG. 7, Zp is illustrated approximately half wayalong the thread) can be calculated with Formula I set out in theDetailed

FIGS. 8 (a), 8(b), 8(c) and 8(d) are a series of photographs of a steelstud after insertion of the steel stud anchor of the present inventionas it is progressively threaded into the steel stud to demonstrate theprogression of a steel stud anchor through a steel stud. FIG. 8(a) showsthe steel stud as approximately the first ¼ of the anchor has beeninserted; FIG. 8(b) shows the steel stud as approximately ½ of theanchor has been inserted; FIG. 8(c) shows the steel stud asapproximately ¾ of the anchor has been inserted; and FIG. 8(d) shows thesteel stud shows the steel stud with an anchor fully inserted.

FIG. 9 shows a picture of a steel stud that has had the steel studanchor of the present invention screwed into it and then removed to showhow the thread of the anchor forms an extrusion for more holdingstrength.

FIG. 10 is a chart comparing the steel stud anchor of the presentinvention to a Machine screw and a typical wood deck screw by showingthe relationship of the length of the threaded section versus the radiusand length versus pitch.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a perspective isometric view of millwork 3 fastened to asteel stud wall, showing steel studs 1 vertically arranged in agenerally regular spacing, and supporting wall cladding 2. Steel studanchors 5 penetrate the back board 4 of the millwork 3, the rear planeof said backboard being contiguous with the generally vertical plane ofthe wall cladding 2. In this fashion, the millwork may bear a specificload, exemplified by a kitchen cabinet full of dishes. Other possibletypes of millwork include bookshelves, television mounts, audioequipment, artwork, mirrors, lighting, drapery, decorative millworkpanels, handrails, conduit mounts and duct hangers. The load variable isa function of the wall material. The steel studs generally used inbuildings for the erection of interior partitions can vary in thicknessfrom about 0.0179″ (18 mils) or 0.455 mm (25 gauge) to about 0.0296″ (30mils) or 0.752 mm (20 gauge) With thicker steel studs, the metal isheavier, sturdier and less malleable, which allows for more weight to beloaded. In certain embodiments, the steel stud anchors are made fromnonferrous metals, such as zinc, zinc alloys, copper, and aluminum basedalloys. In certain other embodiments, the anchors are made from ferrousmetal die castings. In preferred embodiments the steel stud anchor iscomposed of zinc alloy. In preferred embodiments, the wall material isdrywall and steel studs. The gauge of the steel stud can be from about0.0179″ (18 mils) 0.455 mm (25 gauge) to about 0.0296″ (30 mils) 0.752mm (20 gauge) and most preferably about 0.0179″ (18 mm).

Although it is theoretically possible to have a stud made of a varietyof metals, in view of current building codes, the only steel stud incurrent use is a zinc-coated steel stud. the zinc is a coating used toprotect the steel from oxidization, such that the zinc oxidizes overtime but seals in the steel keeping it from breaking down throughoxidization or rust. Thus, the zinc coating gives the steel studs a muchgreater lifespan.

In FIG. 2, a steel stud anchor is shown in isometric view with a centralvoid 6 surrounded by Philips tightening features 7 in the head 8 whichis surrounded by a flange 9. A thread 12 with a variable pitch 10 adornsor extends from the shaft 11, the profile 13 of the shaft 11 having anauger zone 14 nearer the cutting blade 15 and piercing tip 16. The augerzone is the stretching out of the hole and the curling of the metal ofthe stud to the steel stud anchor. With a standard prior art straightscrew with a linear pitch, as the screw is inserted past the drywallinto the steel stud, the material of the drywall is turned to dust andsmall debris is caught up in the threads of the screw. As the head ofthe screw hits the drywall face, it compacts all the debris (nothing hasbeen removed and a screw has been added). This causes an over packingissue and the drywall or millwork will blister from the added pressure.In contrast, the anchor of the present invention has a non-linear taperand variable pitch thread. The fine thread pitch at the tip of theanchor first passes through the drywall and into the steel stud. Thepitch on the part of the anchor not yet passed through the drywall andsteel stud is larger. Thus, the variable diameter of the anchorincreases as the anchor is inserted farther through the drywall andsteel stud. The thread then acts as an augur, pushing the dust anddebris out of the hole (onto the floor). About ⅓″ of the way into thewall, the larger diameter of the threads will have cleared the debrisfor the smaller (core of the anchor). When the anchor is fully insertedthrough the drywall and steel stud, it bottoms out with the head of theanchor flush against the drywall, such that there is no over packingissue.

As explained above, the thread pitch” describes the number of rotationsof the thread per linear unit of shaft length. The thread of the presentinvention preferably has a “non-linear” pitch, wherein the thread countvaries along the long axis of the fastener shaft. Similarly, the threadprofile of the anchor (i.e. the cross-sectional shape and dimensions ofthe thread ridge as it winds around the shaft) is also preferablynon-uniform along the thread helix. The non-linear thread pitch and thenon-uniform thread profile helps the anchor wedge its way in to thesteel stud and prevents the thin metal of the steel stud from jumpingover the threads of the anchor so they do not strip. It also graduallyforms and enlarges the steel stud hole in a manner that increases itsstrength as an anchor point.

In FIG. 3(a), a top view of a steel stud anchor of the present inventionis shown. FIG. 3(b) shows a cross-sectioned view of the steel studanchor to reveal the inner profile of the anchor. A verticalcross-section of the top view reveals a tightening end or head 8containing a void 6 defined by a bore wall 18 equipped with tighteningfeatures 17 along a portion of the void 6. A cutting thread 12 withnon-linear pitch 10 adorns, or extends from, the anchor shaft 11. Aslightly grooved secondary thread 33 is located from the top of thecutting thread up to the head of the anchor. The shaft itself has anon-linear progression of diameter along the shaft 11; similarly thethread profile 19 varies along the length of the shaft. A cutting blade15 located on the end of the shaft 11 near the piercing point 16 to cutsand scoops away detritus. The piercing point 16 is able to penetrate thesteel stud, with or without use of a pilot hole.

FIG. 4(a) is a top view of an anchor of the present invention which hasbeen penetrated by a secondary screw. FIG. 4(b) shows a cross-sectionview of a steel stud anchor of the present invention which has beenpenetrated by a secondary screw 20 and in which the details of themating of these two pieces is illustrated. The steel stud anchor 5 cananchor in a steel stud wall, with or without intervening millwork, toform wall anchors upon which objects may be hung, for example, apainting or television, by penetrating the void (i.e. the hole in thecenter of the head of the screw) 6 formed in the head 8 of the steelstud anchor 5 with a secondary screw 20 with a thread 21 to form aload-bearing thread mate. The travel of the secondary screw 20 withinthe anchor 5 is limited by the depth 22 of the anchor void 6, or bycollision of the secondary screw head 23 with the head 8 of the steelstud anchor 5.

In the lateral cross-section presented in FIG. 5, penetration of amillwork surface 30 to make a perforation 26 by an anchor 5 into themillwork 25 and wall cladding 24 results in loose detritus 27.Alternately, said perforation can be pre-drilled. Said detritus 27 isaugered out and away from the conical perforation 26 in the millwork 25and the wall cladding 24, preventing over-packing of the resulting mate.Said over-packing can result in an undesirable bulge that separates themillwork 25 from the wall cladding 24 to which said millwork is supposedto be contiguous. The steel stud anchor comprises an auger zone 14proximal to the anchor tip 16, and a wedge zone 28 distal to the tip 16.A power drill 32 can provide the driving power to insert the anchor. InFIG. 5(b), the bending back of the stainless steel sheet folded into thestud is shown in detail, where a rim 31 can be seen to be formed underthe influence of the attack. The rim reinforces the mate (i.e., thesecure fixation of the anchor and the steel stud 1)

In certain embodiments, the steel stud anchor 5 may have a press-fitfinishing cap. This is shown in FIG. 6.

In certain embodiments, the steel stud anchor of the present inventionis made of Zinc, zinc alloys, copper and aluminum alloys. In certainpreferred embodiments, the metal alloy is zinc or a zinc alloy and incertain most preferred embodiments, the zinc is pre-hardened by theIosso hardening process, allowing for die-casting of the anchors,instead of machining, as is necessary with steel stud fasteners.

In preferred embodiments of the present invention, the steel stud anchoris 3.5″ or 8.9 cm in length. In certain preferred embodiments, thediameter of the head of the steel stud anchor is preferably about 17 mmor 21/32″ (or 0.65″) across the head. In certain preferred embodiments,the shaft directly below the head is ⅜″ or 9.5 mm in diameter. Inpreferred embodiments, the maximum thread height near the top of theshaft (i.e. closer to the head) is approximately 3/16″. At this samepoint, the thread is approximately ⅛″ thick. The minimum thread heightnear the tip is approximately 1/16″. At this point, the thread isapproximately 1/16″ wide. The heights and spacing are described byformula 1 (in formula 1, they are described as decimals, rather thanfractions of an inch).

The taper and thread frequency follow the relationship shown in FIG. 7.

As illustrated in FIG. 7, and in accordance with an embodiment of thepresent invention, the Radius and Pitch of the steel stud anchor at apoint Zp along the thread (in FIG. 7, Zp is illustrated approximatelyhalf way along the thread) can be calculated with Formula I below:

Radius=((Zp/Lt)^(Pv)×(Rmax−Rmin))+Rmin  Formula I

Pitch=((Zp/Lt)×(Pmax−Pmin))+Pmin  Formula II

Variables

Zp=The Position along the thread you want to know the radius or PitchLt=The Length of the threaded section (in our example Lt=2.75″)

Lt≧1.0″ Lt≦3.5″

Rmax=Maximum Radius of the thread measured from a centerline through theshaft at the head end of the anchor. (In our example Rmax=0.3125″)R max≧0.125″ R max≦0.375″Rmin=Minimum Radius of the thread measured from a centerline through theshaft at the tip of the anchor (In our example Rmin=0.0925″)Rmin>0.040″ R min≦0.1875″Pmax=Maximum Pitch at the head end of the anchor (In our examplePmax=0.3125″)P max≧0.1875″ P max≦0.625″Pmin=minimum Pitch at the tip end of the anchor (In our examplePmin=0.125″)P min≧0.040″ P min≦0.1875″Pv=Power value that creates (In our example Pv=2.0)

Pv≧1.0 Pv≦5.0

FIGS. 8 (a)-8(d) are a series of photographs of a steel stud afterinsertion of the steel stud anchor of the present invention as it isprogressively threaded into the steel stud. The photographs show theincreasing bending back and/or curling of the hole opening in the steelstud which is folded into the stud, with an increasing rim seen as theanchor is inserted further into the stud. The bit of curled metal behindthe steel stud makes it extremely difficult to pull the anchor out orfor it to come loose. This is because the folding of the metal makes itfar stronger near the fold and makes it nearly impossible to pull theanchor out or for it to come loose.

FIG. 9 shows a picture of a steel stud that has had the steel studanchor of the present invention screwed into it and then removed to showhow the thread of the anchor forms an extrusion for more holdingstrength. As can be seen, when the anchor is threaded into the hole, thehole is slowly stretched out while the displaced metal of the steel studis curled into a ring tightly around the anchor. The hole is notcircular but it slightly elongated to one side and as the anchor isinserted through the hole, there is a forming of the material of thesteel stud on the back side which increases the contact area of steelstud on the thread and ultimately results with full or almost fullcontact completely around the thread.

The steel stud anchor of the present invention can be used for hangingcabinets by using the anchor to drill through the cabinet, drywall andinto the steel stud, for French cleats by drilling through the cleat,drywall and into the steel stud, for shelving by drilling through thedrywall and into the steel stud, and then using a screw to fasten theshelving to steel stud anchor. Simply explained, when it is desired toaffix something to a wall, e.g. a shelf bracket, it is possible to drilla pilot hole, then screw the steel stud anchor of the present inventioninto the wallboard after which the small bracket hole would be lined upover the anchor and a then a #8 or #10 convention screw (either wood ormetal) could be threaded into the steel stud anchor of the presentinvention. Window treatments can also be made by drilling through themounting plate, drywall and into steel stud and then using a screw tofasten the mounting plate to steel stud anchor. The steel stud anchorcan also be used to hand televisions, speakers, artwork, mirrors and anyother heavy object to be mounted to a wall surface.

FIG. 10 is a chart comparing the steel stud anchor of the presentinvention to a Machine screw and a typical wood deck screw by showingthe relationship of the length of the threaded section versus the radiusand length versus pitch. The data for this chart is present below inTable 1.

TABLE 1 ¼-20 Ma- Wood chine deck Screw Screw Radius Pitch #8 Ma- Ma-Radius Pitch Radius (steel chine chine Wood Wood Lp stud anchor) ScrewScrew Screw Screw Pitch 1Shot 0 0.0925 0.125 0.125 0.05 0 0.1 0.050.092572727 0.128409091 0.125 0.05 0.025 0.1 0.1 0.092790909 0.1318181820.125 0.05 0.055 0.1 0.15 0.093154545 0.135227273 0.125 0.05 0.075 0.10.2 0.093663636 0.138636364 0.125 0.05 0.085 0.1 0.25 0.0943181820.142045455 0.125 0.05 0.085 0.1 0.3 0.095118182 0.145454545 0.125 0.050.085 0.1 0.35 0.096063636 0.148863636 0.125 0.05 0.085 0.1 0.40.097154545 0.152272727 0.125 0.05 0.085 0.1 0.45 0.0983909090.155681818 0.125 0.05 0.085 0.1 0.5 0.099772727 0.159090909 0.125 0.050.085 0.1 0.55 0.1013 0.1625 0.125 0.05 0.085 0.1 0.6 0.1029727270.165909091 0.125 0.05 0.085 0.1 0.65 0.104790909 0.169318182 0.125 0.050.085 0.1 0.7 0.106754545 0.172727273 0.125 0.05 0.085 0.1 0.750.108863636 0.176136364 0.125 0.05 0.085 0.1 0.8 0.111118182 0.1795454550.125 0.05 0.085 0.1 Pitch (steel stud anchor) 0.85 0.1135181820.182954545 0.125 0.05 0.085 0.1 0.9 0.116063636 0.186363636 0.125 0.050.085 0.1 0.95 0.118754545 0.189772727 0.125 0.05 0.085 0.1 10.121590909 0.193181818 0.125 0.05 0.085 0.1 1.05 0.1245727270.196590909 0.125 0.05 0.085 0.1 1.1 0.1277 0.2 0.125 0.05 0.085 0.11.15 0.130972727 0.203409091 0.125 0.05 0.085 0.1 1.2 0.1343909090.206818182 0.125 0.05 0.085 0.1 1.25 0.137954545 0.210227273 0.125 0.050.085 0.1 1.3 0.141663636 0.213636364 0.125 0.05 0.085 0.1 1.350.145518182 0.217045455 0.125 0.05 0.085 0.1 1.4 0.149518182 0.2204545450.125 0.05 0.085 0.1 1.45 0.153663636 0.223863636 0.125 0.05 0.085 0.11.5 0.157954545 0.227272727 0.125 0.05 0.085 0.1 1.55 0.1623909090.230681818 0.125 0.05 0.085 0.1 1.6 0.166972727 0.234090909 0.125 0.050.085 0.1 1.65 0.1717 0.2375 0.125 0.05 0.085 0.1 1.7 0.1765727270.240909091 0.125 0.05 0.085 0.1 1.75 0.181590909 0.244318182 0.125 0.050.085 0.1 1.8 0.186754545 0.247727273 0.125 0.05 0.085 0.1 1.850.192063636 0.251136364 0.125 0.05 0.085 0.1 1.9 0.197518182 0.2545454550.125 0.05 0.085 0.1 1.95 0.203118182 0.257954545 0.125 0.05 0.085 0.1 20.208863636 0.261363636 0.125 0.05 0.085 0.1 2.05 0.2147545450.264772727 0.125 0.05 0.085 0.1 2.1 0.220790909 0.268181818 0.125 0.050.085 0.1 2.15 0.226972727 0.271590909 0.125 0.05 0.085 0.1 2.2 0.23330.275 0.125 0.05 0.085 0.1 2.25 0.239772727 0.278409091 0.125 0.05 0.0850.1 2.3 0.246390909 0.281818182 0.125 0.05 0.085 0.1 2.35 0.2531545450.285227273 0.125 0.05 0.085 0.1 2.4 0.260063636 0.288636364 0.125 0.050.085 0.1 2.45 0.267118182 0.292045455 0.125 0.05 0.085 0.1 2.50.274318182 0.295454545 0.125 0.05 0.085 0.1 2.55 0.2816636360.298863636 0.125 0.05 0.085 0.1 2.6 0.289154545 0.302272727 0.125 0.050.085 0.1 2.65 0.296790909 0.305681818 0.125 0.05 0.085 0.1 2.70.304572727 0.309090909 0.125 0.05 0.085 0.1 2.75 0.3125 0.3125 0.1250.05 0.085 0.1

As can be seen from both Table 1 and FIG. 10, the steel stud anchor ofthe present invention has a linear thread pitch but it is on a slope,indicating that it is getting larger. The steel stud anchor of thepresent invention gets larger in a linear fashion. In contrast, and asseen on the chart, a wood screw and machine screw have a constant linearpitch. When a comparison is made of the radius of the threads versus thelength of the steel stud anchor of the present invention, a curve ofnon-linear sizes are plotted. In contrast, those of a wood or machinescrew are constant, with the exception of the wood screw that has apointed tip for centering and entering wood. The combination of alinear, but increasing, pitch coupled with a non-linear concave curvedprofile helps form the steel stud as the steel stud anchor passesthrough it, providing for more strength.

21. A method of installing a steel stud anchor through a wall claddingand a steel stud to form a load-bearing mate comprising: (1) screwingthe anchor through the wall cladding and then into the steel studlocated behind the wall cladding; (2) forming a comma shaped opening inthe steel stud as the anchor is screwed through the steel stud, suchthat the opening is wider at one end and is slightly elongated to oneside at an opposing end; and (3) displacing the metal of the steel studsuch that the displaced metal of the steel stud pushes through theopening and then bends back or curls onto the anchor to hold the anchorin place, wherein the anchor is comprised of a head, a shaft and a tipand has a threaded portion extending along a length of the shaft. 22.The method of claim 21, wherein the threads extend in a non-linear pitcharound the length of the shaft in a linear progression.
 23. The methodof claim 21, wherein the shaft diameter has a non-linear progressionalong the length of the shaft, and wherein the threads extend in anon-linear pitch around the length of the shaft in a linear progression24. The method of claim 21, wherein the shaft has a concave curvedprofile.
 25. The method of claim 21, wherein a pitch and a radius of thethread is defined by Formula I and Formula II as follows:Radius=((Zp/Lt)Pv×(Rmax−Rmin))+Rmin  Formula IPitch=((Zp/Lt)×(Pmax−Pmin))+Pmin  Formula II wherein Zp is a Positionalong the thread, Lt is a Length of the threaded section of the shaft,Rmax is a Maximum Radius of the thread measured from a centerlinethrough the shaft at a head end of the anchor, Rmin is a Minimum Radiusof the thread measured from a centerline through the shaft at a tip ofthe anchor, Pmax is a Maximum Pitch at the head end of the anchor, Pminis a minimum Pitch at an end of the pointed tip of the anchor Pv is aPower value.
 26. The method of claim 25, wherein Lt≧1.0″ Lt≦3.5,Rmax≧0.125″ Rmax≦0.375″, Rmin>0.040″ Rmin≦0.1875″, Pmax≧0.1875″Pmax≦0.625, Pmin≧0.040″ Pmin≦0.1875″, and Pv≧1.0 Pv≦5.0.
 27. The methodof claim 21, wherein the steel stud anchor is made of zinc or a zincalloy.
 28. The method of claim 21, wherein step 1 further comprisesdriving the anchor into the wall cladding and into the steel stud duringa first revolution of the threaded portion such that the only about ⅛″of the anchor is in or has passed through the wall cladding and anadjacent portion of the anchor that has not yet entered or passedthrough the steel stud has a larger pitch than the ⅛″ of the anchor thathas entered or passed through the steel stud, with the larger pitchacting as an auger as it enters the wall cladding, pushing debris fromthe perforation in the wall cladding out of the way for the anchor. 29.A method of wedging a steel stud anchor into a steel stud and preventingthe metal of the steel stud from jumping over the threaded portion ofthe shaft so the anchor does not strip using the method of claim
 21. 30.The method of claim 21, further comprising drilling a pilot hole beforethe steel stud anchor is threaded through the wall cladding and steelstud.
 31. The method of claim 21, wherein the shaft includes a blade forclearing away debris from the hole.
 32. A method of installing a steelstud anchor through a wall cladding and a steel stud to form aload-bearing mate comprising: (1) threading the anchor through the wallcladding to form a conical perforation in the wall cladding, said anchorbeing comprised of a head, a tip and a shaft having a threaded portionextending along a length of the shaft, with the shaft comprising anauger zone proximal to the tip, and a wedge zone distal to the tip; (2)threading the anchor into the steel stud located behind the wallcladding; (3) threading the auger zone of the anchor through the wallcladding such that the threads of the auger zone stretch the conicalperforation in the wall cladding so that the threads act as an auger andpush the debris out of the conical perforation in the wall cladding in adirection opposite from the steel stud; (4) continuing the threading ofthe anchor through the wall cladding and the steel stud until a portionof the wedge zone has passed through the steel stud and a second portionof the wedge zone is located within the steed stud.
 33. The method ofclaim 32, further comprising threading the anchor through the wallcladding and the steel stud until a top grooved zone on the shaftadjacent to the head sits within the wall cladding.
 34. The method ofclaim 32, further comprising displacing the metal of the steel stud suchthat the displaced metal of the steel stud pushes through the openingand then bends back onto the threads of the anchor around the anchor tohelp hold the anchor in place, with the bending back of displaced metalbeginning as the auger zone is threaded through the steel stud andfurther comprising stopping the threading of the anchor when a portionof the wedge zone is located within the steel stud, wherein the threadedportion has a variable pitch extending from the wedge zone through theauger zone.
 35. The method of claim 32, wherein step 2 further comprisesan increasing diameter of the shaft of the steel stud anchor pulling thehole in the steel stud open as the steel stud anchor is threaded throughthe steel stud, while the steel stud anchor thread also begins totightly bend or curl the displaced metal of the steel stud around theanchor to form an increasing rim, allowing for increased surface areabetween the anchor and the steel stud to reinforce the holding of theanchor in the steel stud and secure fixation of the steel stud anchor inthe steel stud.
 36. The method of claim 32, wherein a pitch and a radiusof the thread is defined by Formula I and Formula II as follows:Radius=((Zp/Lt)Pv×(Rmax−Rmin))+Rmin  Formula IPitch=((Zp/Lt)×(Pmax−Pmin))+Pmin  Formula II wherein Zp is a Positionalong the thread, Lt is a Length of the threaded section of the shaft,Rmax is a Maximum Radius of the thread measured from a centerlinethrough the shaft at a head end of the anchor, Rmin is a Minimum Radiusof the thread measured from a centerline through the shaft at a tip ofthe anchor, Pmax is a Maximum Pitch at the head end of the anchor, Pminis a minimum Pitch at an end of the pointed tip of the anchor Pv is aPower value.
 37. The method of claim 36, wherein Lt≧1.0″ Lt≦3.5,Rmax≧0.125″ Rmax≦0.375″, Rmin>0.040″ Rmin≦0.1875″, Pmax≧0.1875″Pmax≦0.625, Pmin≧0.040″ Pmin≦0.1875″, and Pv≧1.0 Pv≦5.0.
 38. The methodof claim 32, wherein the steel stud anchor is made of zinc or a zincalloy.
 39. The method of claim 32, wherein the shaft diameter has anon-linear progression along the length of the shaft, and wherein thethread extends in a non-linear pitch around the length of the shaft in alinear progression
 40. The method of claim 32, further comprisingscrewing an auger zone of the threaded portion of the shaft through thewall cladding such that the threads of the auger zone stretch theconical perforation in the wall cladding so that the threads act as anauger and push the debris out of the conical perforation in the wallcladding in a direction opposite from the steel stud; (5) continuing thescrewing of the anchor through the wall cladding and the steel studuntil a portion of a wedge zone adjacent to the auger zone has passedthrough the steel stud.
 41. The method of claim 32, further comprisingdrilling a pilot hole before the steel stud anchor is threaded throughthe wall cladding and steel stud.
 42. A method of installing a metalfastener in a steel stud to form a load-bearing mate comprising: (1)threading the fastener into the steel stud, said fastener having a head,a conically shaped shaft and a pointed tip, with the shaft extendingfrom the head to the pointed tip and having a top grooved zone adjacentto the head and a threaded portion adjacent to the grooved zone andextending to the pointed tip, said threaded portion having an auger zoneproximal to the pointed tip and a wedge zone distal to the tip, whereinthe shaft diameter has a non-linear progression along the length of theshaft, and wherein the threads extend in a non-linear pitch around thelength of the shaft in a linear progression and wherein the head has acentral void including a screw drive, wherein the central void extendsinto the shaft; (2) continuing to thread the fastener through the steelstud until at least a portion of the wedge zone resides within the steelstud.
 43. The method of claim 42, wherein a pitch and a radius of thethread is defined by Formula I and Formula II as follows:Radius=((Zp/Lt)Pv×(Rmax−Rmin))+Rmin  Formula IPitch=((Zp/Lt)×(Pmax−Pmin))+Pmin  Formula II wherein Zp is a Positionalong the thread, Lt is a Length of the threaded section of the shaft,Rmax is a Maximum Radius of the thread measured from a centerlinethrough the shaft at a head end of the metal fastener, Rmin is a MinimumRadius of the thread measured from a centerline through the shaft at atip of the metal fastener, Pmax is a Maximum Pitch at the head end ofthe metal fastener, Pmin is a minimum Pitch at an end of the pointed tipof the metal fastener Pv is a Power value.
 44. The method claim 43,wherein Lt≧1.0″ Lt≦3.5, Rmax≧0.125″ Rmax≦0.375″, Rmin>0.040″Rmin≦0.1875″, Pmax≧0.1875″ Pmax≦0.625, Pmin≧0.040″ Pmin≦0.1875″, andPv≧1.0 Pv≦5.0.
 45. The method of claim 42, wherein the metal fastener ismade of zinc or a zinc alloy.
 46. The method of claim 42, wherein themaximum thread height occurs adjacent to the top grooved zone and themaximum thread height is about 3/16″ and wherein the minimum threadheight occurs in the top grooved zone adjacent to the head of the metalfastener and is about 1/16″.
 47. The method of claim 42, wherein theanchor is concentrically penetrated by a generally conical cavity partlyextruding into the shaft from the head of the fastener, said conicalcentral void extending approximately 1″ from the head into the shaftsuch that the conical central void extends through about 28% of thelength of the shaft, with the remaining about 72% of the shaft beingsolid.
 48. The method of claim 42, wherein the shaft has a concavecurved profile.
 49. A method of installing a metal fastener in a steelstud to form a load-bearing mate comprising threading the fastener intothe steel stud wherein the fastener comprises: a fastener head equippedwith tightening features around a central void a threaded, generallyconical shaft with curved sides in cross-section that meet at a tip, alinear progression in thread pitch along the length of the shaft, athread profile that changes with position along the thread, a non-linearprogression of shaft diameter along the length of the shaft, a piercingpoint at the distal end of the generally conical shaft wherein thethreaded shaft has an auger zone proximal to the tip having threads forstretching a hole in the steel stud and for pushing debris out of theway as the fastener is inserted through the steel stud and has a wedgezone proximal to the auger zone for further enlarging a hole in thesteel stud and having threads for forming an increasing rim around thehole in the steel stud formed from the steel stud material to wedge theanchor in the steel stud and prevent it from jumping over threads of thethreaded shaft so it does not strip the steel stud anchor.
 50. A methodof installing a metal steel stud anchor in a steel stud to form aload-bearing mate comprising threading the anchor into the steel studwherein the anchor comprises a head, a shaft and a pointed tip: whereinthe shaft is conically shaped and extends from the head to the pointedtip, with the shaft having a top grooved zone adjacent to the head and athreaded portion adjacent to the grooved zone and extending to thepointed tip, wherein the shaft diameter has a non-linear progressionalong the length of the shaft, and wherein the threads extend in anon-linear pitch around the length of the shaft in a linear progressionand wherein the head has a central void, wherein the central voidextends into the shaft and wherein the shaft has a concave curvedprofile.